The Covid vaccine by Sinovac Biotech Ltd can not produce enough antibodies to neutralise the highly modified coronavirus strain Omicron, said new research from the University of Hong Kong.
Sinovac's CoronaVac is one of the most widely used vaccines in the world. According to the findings of a recent study conducted by Hong Kong researchers, this could have far-reaching
implications for the millions of people who rely on the Chinese shot to protect them from Covid-19.
According to scientists, both the Sinovac vaccine and a Pfizer-BioNTech vaccine demonstrated "inadequate" antibody responses to the newly discovered strain.
As per the statement released by a team of researchers from the University of Hong Kong, none of a group of 25 people fully vaccinated with Sinovac's Coronavac vaccine had adequate antibodies
in their blood serum to neutralise the omicron variant.
Meanwhile, five of the 25 people who were fully vaccinated with the messenger RNA shot created by Pfizer Inc. and BioNTech SE were able to neutralise the new variant, according to the researchers.
This is in accordance with the firms' findings from last week, which stated that a third shot would be adequate to protect against omicron.
The study of 50 participants, led by Kwok-Yung Yuen, a renowned infectious diseases professor at the University of Hong Kong, has been accepted for publication in the medical journal Clinical
Infectious Diseases and is available online as a pre-print.
Setback to CoronaVac receivers
For now, information about the vaccine, such as - how Sinovac's shot reacts to omicron; how T cells, the immune system's weapon against virus-infected cells, will respond - remains
unclear.
The findings of the Hong Kong University have come as a major setback to those who have received the 2.3 billion doses of CoronaVac that were shipped out, mostly to China and other developing
countries.
The possibility of having to re-vaccinate against the new strain, which is considered to be at least four times as transmissible as the delta variation in Japan research, may put back the
world's attempts to end the pandemic.
According to experts, if Sinovac is proved to be ineffective against omicron in more comprehensive studies, China, which has managed to shield the great majority of its population from Covid-19
by tight borders and strict containment measures, will be the most vulnerable to the new variant.
The government has given out 2.6 billion indigenous vaccines to its 1.4 billion people, many of which were Coronavac. Now the country faces the possibility of having to develop new vaccines
and roll them out again before it can move away from its current isolationist stance.
Natural Immunity could ensure "no major impact"
Previous infection waves in other countries using Coronavac would have bestowed some natural immunity, which would help assure "no major impact" from omicron, said Benjamin Cowling,
an epidemiology professor at the University of Hong Kong.
However, people of mainland China and Hong Kong have never been exposed to a large-scale infection. This makes them vulnerable.
"The Chinese government has worked hard to achieve a high vaccination rate across the country, but the virus's mutability has significantly reduced the impact of those efforts,"
said Nicholas Thomas, an associate professor at City University of Hong Kong.
China now faces two big challenges- first, to ensure that their population is again protected from omicron and any future mutations and second, managing the flows of goods and people across
their borders as the rest of the world adjusts to living with the virus.
So, what's next?
According to reports, the Hong Kong research team has sent the isolated omicron virus to the Chinese government and vaccine manufacturers for the production of vaccines against the new variant.
Sinovac said last week that it was looking into how well its vaccine works against omicron, but gave no timeframe for when the results would be released.
While waiting for the next generation of vaccines, scientists encouraged the public to get a third dose of the vaccine as soon as feasible. However, it needs to be seen whether a third dosage
of the current Sinovac vaccine can increase the neutralising antibody response against the omicron.